Method of treating diseases of the mucous membrane using compounds of a thiazolidine carboxylic acid and pharmaceutical preparations thereof

ABSTRACT

MUCLOYTIC AND ANTITUSSIVE MEDICAMENT COMPRISING DERIVATIVES OF THAIZOLIDINE CARBOXYLIC ACID OF THE FORMULA,   2-R1,3-R3,4-(R2-CO-)THIAZOLIDINE   WHEREIN R1 REPRESENTS HYDROGEN, AND ALKYL, ARYL, HYDROXYL, ALKYLOXY, ARYLOXY, HETEROCYCLIC, AMINO OR CARBOYXLIC ACID OR ESTER, ALL OF THESE GROUPS CAPABLE OF BEING SUBSTITUTED, WHETHER SUBSTITUTED OR NOT; R2 REPRESENTS AN AMINO, HYDROXY, ALKYLOXY, ARYLOXY, HETEROCYCLIC, MONO- AND DIALKYLAMINO, -NHCH2OH, OR MORPHOLINE RADICAL, ALL OF THESE GROUPS CAPABLE OF BEING SUBSTITUTED, WHETHER SUBSTITUTED OR NOT; AND R3 REPRESENTS HYDROGEN, AN ALKYL, INCLUDING CYCLOALKYL HETEROCYCLIC, ARYL, CARBOXYLIC ACID OR CARBOXYLIC ACID ESTER GROUP.

METHOD OF TREATING DISEASES OF THE MUCOUS MEMBRANE USING COMPOUNDS OF A THIAZOLIDINE CARBOXYLIC ACID AND PHARMACEUTICAL PREPARATIONS THEREOF Francois Robert Bertrand, Geneva, Switzerland, asslgnor to Medial de Toledo & Cie, Geneva, Switzerland No Drawing. Continuation-in-part of abandoned application Ser. No. 889,293, Dec. 30, 1969. This application Dec. 30, 1971, Ser. No. 214,479 Claims priority, application France, Dec. 31, 1968,

Int. Cl. A61k 27/00 US. Cl. 424-270 ABSTRACT OF THE DISCLOSURE Mucolytic and antitussive medicament comprising de rivatives of thiazolidine carboxylic acid of the formula,

HzCCH--COR7 S H N-Ra wherein R represents hydrogen, an alkyl, aryl, hydroxy, alkyloxy, aryloxy, heterocyclic, amino or carboxylic acid or ester, all of the these groups capable of being substituted, whether substituted or not;

R represents an amino, hydroxy, alkyloxy, aryloxy, heterocyclic, monoand dialkylamino, -NHCH OH, or morpholine radical, all of these groups capable of being substituted, whether substituted or not; and

R represents hydrogen, an alkyl, including cycloalkyl, heterocyclic, aryl, carboxylic acid or carboxylic acid ester group.

H (lJCHCORr S H I i-Rs wherein R represents hydrogen, an alkyl, aryl, hydroxy( alkyloxy, aryloxy, heterocyclic, amino or carboxylic acid or ester radical, all of these groups capableof being substituted,

whether substituted or not;

R represents an amino, hydroxy( alkyloxy, aryloxy, heterocyclic, monoor dialkylamino, --NHCH OH, or morpholine radical, all of these groups capable of being substituted, whether substituted or not; and

R represents hydrogen, an alkyl, heterocyclic, ar:yl, earboxylic acid or carboxylic acid ester group.

In the above formula, alkyl includes straight,-branched' andcyclic alkyl groups; however, the alkyl-groups. are; preferably lower alkyl groups containing up to 6 carbon- 8 Claims- United States Patent ice atoms and more preferably up to 4 carbon atoms. The cyclicgroup including heterocyclic groups are preferably those containing 5 or 6 members in the ring and aryl is preferably phenyl.

Evenmore preferably, in the formula above, R is hydrogen, methyl or ethyl; R is OH, methyl, ethyl, amino, methylamino and dimethylamino or Z-aminothiazolidines and R is H or methyl.

It is also understood that the non-toxic salts of the thiozolidine derivatives, such as the hydrochloride of ester derivatives and the sodium salt of the acid, are included within the compounds used in accordance with the present invention.

The envisaged compounds can be prepared by reacting thioamino acids where --SH and -NH groups are fixed on two neighboring carbons with an aldehyde in such away as to induce closure to form a thiazolidine nucleus. This procedure can usually be carried out in water or sometimes in an alcoholic medium.

EXAMPLES OF PREPARATION OF THE THIOZOLIDINE COMPOUNDS Example 1 Preparation of Z-methylthiazolidine-4-carboxylic acid (Product MG 238") by the reaction:

1 PROCESS A current of nitrogen is circulated in a 2 l. reactor,

. fitted with an agitator, a refrigerant, a thermometer and 15-20 C. for hr. to 1 hr., cooling with cold water if necessary. The cysteine dissolvesand agitation is con-v tinuedfor 3 hr; at 20 C. and then 1 hr. at 40 C. to effect the reaction. It is left overnight at normal temperature. A slight precipitation occurs and the mixture is filtered until clear with a Buchner filter pH 3.8-4.0.

The reaction is decanted into a 3 l. flask and 850 ml.

of water is distilled. in a vacuum. To the residue, 1 liter of absolute alcohol is added slowly and stirred. This is agitated then left to crystallize in a refrigerating machine.

The product crystallizes slowly in the form of a voluminous precipitate. It is passed through a large Buchner filter of 24 cm., drained carefully, and then washed with 3 portions of ml. of absolute alcohol. The precipitate is dried in a vacuum at 70 C., to constant weight. The substance is next sieved and drying is carried out by means of a CaCl dessicator in a vacuum.

Characteristics of the product: Weight, 275 g., fusion, 158 to 160 degrees; yield, th. 328.2 g. (2.23 M)v 84%. The product is white, finely crystalline, forming a felt -:-of light and columinous crystals.

3 RECRYSTALLIZATION 2-methylthiazolidine-4-carboxylic acid in an amount of 20 g. is dissolved in 80 ml. of distilled water at 90 degrees and filtered hot in the presence of a small amount of carbon; then 400 ml. of absolute alcohol is added. It is left to crystallize overnight in a refrigerating machine. After filtering, washing and drying in a vacuum at 70 C. 12 g. of the product are obtained; fusion, 163 to 164 C.; yield, 60%.

SOLUBILITY The Z-methyltbiazolidine 4-carboxylic acid is soluble in the proportion of 1 g. 12 m1. of water at 20 C. or 1 g. in 40 ml. of methanol or ethanol at 20 C.

REMARKS EXAMPLES 2 AND 3 Preparation of MG 238 ester and amide 7 not onion s NERO! 5 NH N301 CH: CH:

colon, CONE: cmon NH4C1 l l 4- 2NH; r S NILHCI S NH om om iPreparation of themethyl ester of MG 238 A suspension of 100 g. of product No. 238 is saturated for 6 to 8 hours at 20 with a gaseous current of hydrochloric acid in 1v liter of methanol. Gradually the mixture becomes homogenous. It is then heated to reflux and left overnight; dry concentration is carried out in a vacuum. The residue is treated with 500 ml. of ether and then left to crystallize. Thus, 134g. of the hydrochloride of the methyl ester is obtained.

- To prepare the ester base, 20 g. of this hydrochloride in 100 ml. of methanol with a solution of 2.3 g. of sodium methylate, a dry concentration is made in a vacuum. The oily residue is distilled in a high vacuum at a pressure of 1 mm. Hg and g. of ester base is obtained.

Preparation of the amide of product 238 A solution of 100 g. of the hydrochloride of the methyl ester of 238 is saturated at 0 to 10 C. with a current of dry ammonia in 1 liter of methanol. The saturation lasts about 6 hours. It is left in the ambient temperature for two days. 'It is heated for 1 hour to 30, then the excess ammonia and the methanol are distilled in a vacuum. The dry residue is treated by boiling with 250 ml. of isopropanol. The ammonium chloride is filtered andthe solution is left in a refrigerating machine whereby'the amide crystallizes. Thus, 60 g. of crystalline product are obtained.

a .METHOD OF ANALYSIS These compounds can be analyzed quantatively, either by potentiometric measurement with l N perchloric acid or by alkali-acidimetric measurement with tetrabutyl ammonium, 1 N hydroxide and with methyl violet as an indicator.

TOXICOLOGICAL PROPERTIES PHARMACOLOGICAL PROPERTIES A series of these substances have been tested in vitro to determine their mucolytic effect, in comparison with the action of a physiological solution of NaCl used as a control.

These tests have shown that in this family of compounds, products which lower the viscosity from 20% to 40% after five minutes, from 30% to 55% after 10 minutes, from 35% to 60% after 15 minutes, are obtained. From among this series of derivatives and for very searching pharmacological and clinical tests, the 2-methylthiazolidine-4-carboxylic acid of the following developed formula (MG 238) was chosen:

' This is awhite, odorless, relatively light, finely crystallized product; fusion point, 163 C. to 164 C. (uncorrected).It is very soluble in'w'ater as well as in most alcohols, and other organic solvents. The product obtained by synthesis has an optically active form, providing the starting point is L-cysteine. A levogyrate form for this product is alsoobtained.

Toxicological action of compound MP 238 1. Acute toxicity.The administration of doses less than3000 mg./-kg. produces no mortality in animals. The DL 50 under these conditions has no significance, the volume of the administered doses leading then rapidly to DL 100. 1

The subcutaneous administration of doses less than 2440 mgJkg. has no fatal effect on animals.

Intraperitonal administration of the compound in less than 2440 mg./kg. has no fatal effect on animals.

2. Subacute toxicity-The chronic administration of compound MG 238 was carried out on the male Wistar rat, for one month and for three months. With doses of 100, 250 and 500 mg./kg. per day, no fatal effects were observed on all of the tested animals.

Determination of the blood formula and examination of the diflcrent organs removed showed no secondary effects from this substance.

Pharmacological activity of MG 238 in vitro The mucolytic activity has been determined for different doses in comparison with a physiological solution of NaCl.

The values of viscosity in centipoises were immediately determined after five minutes, after ten minutes, and after fifteen minutes of contact between the substance and 2 ml. of sputum taken directly from chronic bronchitis patients.

. These tests show that in comparison with a physi ological solution of NaCl, MG 238 clearly lowered the viscosity from which the following indicative values were obtained:

It should be noted that these values were always recalculated in relation to an NaCl solution, fixed at"100% each time.

Pharmacological activity of MG 238 in animals The product was orally administered in the proportion of mg./kg. of bone to horses with chronic bronchitis and even in certain cases, with pulmonary emphysema. After 2 to 4 days of the treatment, according to the case, the disappearance of respiratory troubles was established.

Similarly and with the same doses, tests have ben carried out on dogs; similar results by administering the product orally, in the proportion of 10 mg./kg. of bone,

were thus obtained. e

The following compounds have also given encouraging results:

N-rnethyl- Pharmaceutical forms The product can be orally administered in the form of a powder, pills or bolus to human beings, these forms being obtained after mixing the active product with a certain number of excipients necessary to produce the pharmaceutical form, and with the concentration of the active constituents being, in general 100 mg.

For example, a pill comprises:

2-methylthiazolidine-4-carboxylic acid 100 Milk sugar 90 Polyvinylpyrrolidone 2 Silicic acid 1 Corn starch 46 Magnesium stearate 1 Talc 10 Total for a pill 250 Aqueous solutions can also be employed to carry out treatment by aerosol. Finally, the active product can also be administered as a suppository.

The active constituent can also be incorporated in solutions or suspensions in a mixture of other constituents, in order to obtain a therapeutic antitussive action. It can also be applied in sterile solutions for injections.

For example, a solution intended for injection comm t v 2-rnethylthiazolidine 4-carboxylic acid amide" mg Sodium chloride mg 2.5 Preservative distilled water q.s. ad ml 1 The products with mucolytic activity are often administered from the therapeutic viewpoint, with antibiotics.

Therefore,"examinations have been carried out, also in vitro, to discover if thesubstance MG 238 inhibits the antibiotic 'activity'of the oxytetracycline hydrochloride.

The results of these tests have shown that the association of MG 238 in variable quantities, also variable of oxytetracycline hydrochloride neither provokes an inhibition, nor a potentialization of the antibiotic activity.

Clinical tests The clinical tests have been divided into three distinct groups:

A first group of 20 patients, suffering from chronic bronchial troubles, were treated with solutions of 5%, 10% and 20% of the active substance, by aerosol, in comparison toa saline solution.

The effect of the product, if not very clearly marked with a solution of 5% appears significant, however, and isalmost the same with solutions of 10% and 20%. That is to say,alowering of the viscosity of the sputum can be established and at the same time, an increase in its volume. It also appears that a solution of 20% increases the volume of the secretion too much which can at times provoke bronchial obstructions in patients having difliculty with expectoration.

v The results of the second group of 10 patients will now be given in detail. In this case, a solution with 10% of the active substance was used always in comparison with the same'volume of saline solution, namely 2X2 ml., per day (morning and evening).

Thisae'rosol'treatment produced the following average results with 10'patients:

At the same time a check was carried out and confirmed the results by histochemical determination of the ADN and sMPS filaments of the mucous.

Attention should be drawn to the fact that in other respects, no visible action was observed on the mucous membranes.

Finally, working with the third group of 20 patients with chronic bronchitis, the product was administered to ten cases in the form of 4 to 6 pills of 100 mg., and to the other 10 cases in the form of deep intramuscular injections of 3 ml., of a 20% solution, morning and evening, over a period of seven days, in comparison with 10 untreated sick control patients. Although slower to manifest itself and in lower proportions, the therapeutic effectiveness of the preparation was again demonstrated by the determination of the sputum viscosity and the measurement of its volume. Here, again, the histochemical analyses confirmed the result.

TREATMENT.VISCOSITY MEASUREMENTS OF THE MUCOUS, CASE AVERAGE BY DAY-AFTER INITIAL TREATMENT A significant lowering in viscosity of the mucous in the two cases administered by intramuscular injection or orally, can thus be established. In the last case, how ever, the result is manifested more slowly and the treatment must be more prolonged. Finally, whether administered by normal means or by injection, if this iscarv ried out quite slowly, the very good tolerance of the active substance should be mentioned. 7

What I cairn as new asd desire to secure by Letters Patent is:

1. A method for lowering the viscosity .of mucous in animals and humans which comprises administering to said animals and humans a therapeutic amount of a thiazolidine carboxylic acid of the formula,

wherein R is hydrogen, or a lower alkyl group, ,7 R is hydroxy, lower alkoxy, amino mono-lower-alkylw amino, di-lower alkyl amino or a Z-aminothiazolidine group, and R is hydrogen or lower alkyl. 2. A method according to claim 1 in which in said thia zolidine carboxylic acid,

R is hydrogen, methyl or ethyl, R is hydrogen, amino, methylamino, dimethylamino, methoxy, ethoxy or Z-aminothizolidino, and R is hydrogen or methyl. I I ,3. A method according to claim 1 in which 2-met-hylthiazolidine carboxylic acid is administered. I 4. A method according to claim 1, in which said metho is used for treatment of respiratory diseases.

5. A pharmaceutical composition in pill form having 8 mucolytic' and antitussive properties containing a thiazolidine carboxylic acid compound of the formula, n,c--on-coa,

wherein R is hydrogen, or a lower alkyl group,

R is hydroxy, lower alkoxy, amino mono-lower-alkylamino, di-lower-alkylamino, and

R is hydrogen or lower alkyl, in an amount of about 100 mg. per pill.

6. A pharmaceutical composition in inject-able form having mucolytic and antitussive properties containing a thiazolidine carhoxylic 'acid compound of the formula,

Ha? (DH-COR:

S N-Ra OH is wherein R is hydrogen, or a lower alkyl group, R is hydroxy, lower alkoxy, amino mono-lower-alkylamino, di-lower-alkylamino, and R ishydrogen orlower alkyl, in a concentration of about 20 to 7. A pharmaceutical composition according to claim 5, in which in said thiazolidine carboxylic acid R is methyl R is hydroxy, methoxy and amino R is hydrogen. 8. A pharmaceutical composition according to claim 5 in which in said thiazolidine carboxylic acid R is methyl R is hydroxy, ethoxy and amino R is hydrogen- Q vvReferences Cited Chem. Abst., 59, pp. 591-2 (1903).

STANLEY 'J. FRIEDMAN, Primary Examine. 

